Posted
by
samzenpus
on Thursday March 22, 2012 @07:18PM
from the lightning-leaf dept.

An anonymous reader writes "Everyone knows trees give us all oxygen so we can breathe, but according to Australian scientists, they also affect the concentration of positive and negative ions in the air. A team from the Queensland University of Technology's International Laboratory for Air Quality and Health ran experiments in six locations all over Brisbane and found that positive and negative ion concentrations in the air were two times higher in heavily wooded areas than in open grassy areas, such as parks."

Gaia merely requires that life is dominated by negative feedback loops such that the positive feedback loops are totally suppressed.

What does that mean? That creatures are starving to death when there are too many of them, and that's a negative feedback loop? Shouldn't the negative and positive be in balance? And I thought Gaia meant the earth is conscious, at least that's what I learned from Final Fantasy.

I'll use his example of Daisyworld. In this abstract model, there are two types of daisy - black and white. The black daisies, by lowering the albedo of the surface, warm the local climate up. White daisies, by raising the albedo, cool the local climate down.

If black daisies increased in number when warm, the temperature would rise through a positive feedback loop and they'd cook themselves. They're stable ONLY when they prefer a relatively cool temperature. The opposite is true for white daisies.

The only question then, is how stable/unstable the earth is......for example, killing off the majority of the earth's megafauna hasn't seemed to cause a problem. How delicate is the balance? How hard is it to change it? And also, if something does happen, how far out will it catapult into something different? Will a small change in one variable be magnified many times over?

Agreed. That question is one that worries a lot of climate experts because existing models have to make certain simplifying assumptions - one of which is that the climate can't leap from one "strange attractor" to another, that processes can start and stop but don't catapult between states. However, we know that chaotic systems (and the climate is a chaotic system) do indeed catapult between states. We also know that the degree of change needed for a leap is difficult to predict - there isn't a smooth divis

There is, of course, the possibility of multiple equilibria. Daisyworld is too simple of an example to capture this. Given the complexity of climate, I'd be surprised if we weren't simply at some local optimum. In any case, this is an unresolved question-- conducting the experiment may have some unpleasant consequences;)

Also two of Asimov's Foundation novels. But wikipedia has a more real-world meaning:

The Gaia hypothesis, also known as Gaia theory or Gaia principle, proposes that all organisms and their inorganic surroundings on Earth are closely integrated to form a single and self-regulating complex system, maintaining the conditions for life on the planet.

The scientific investigation of the Gaia hypothesis focuses on observing how the biosphere and the evolution of life

Lovelock's Daisyworld has no consciousness . The idea that Gaia implies consciousness (sometimes referred to as the Strong Gaia hypothesis) is an extension that does not appear to involve James Lovelock or the branches of planetary ecology that he developed. His work tends to be referred to as the Weak Gaia hypothesis in which the planet is an "organism" and "alive", but not conscious.

That isn't the mechanism the paper is proposing. What the authors suggest is that trees uptake radon dissolved in groundwater, transpire it into the air, and that it is the radioactive decay of radon that would be responsible for the ions released by trees.

However, they don't have an insulator creating a space between the leaves and the ground. If this explanation ends up being it, then I would imagine it like being in a very large, air dielectric, capacitor. The ions are dielectric loss in the huge and oddly constructed capacitor. Even though each leaf is small and, while it might build a reasonable voltage, I have never gotten a shock from touching a leaf, so I am thinking there isn't much charge per unit area....but.... all those leaves make for a pretty g

It's not obvious to me that it is true that a "grassy area" has less surface area than a wooded area. You can fit a lot of blades of grass in the space a tree takes up. Now, they say parks, so maybe they're talking about trimmed grass, but untrimmed grass can grow pretty high.

I assume you can push more wind through trees and their leaves than you can through grass. Like you said grass can grow a lot, but in my experience it seems it would be too dense and would just deflect most of the wind over the top of the grass. Of course, this is all speculation, I find it hard to believe this wasn't identified long before now. We have rather detailed real time maps of ion radiation used for many things including the detection of nuclear weapon use.

Then why are alpha, beta, and gamma radiation called "ionizing"? Alpha is a positive helium ion, and beta is an electron.

Note the phrasing: "not all", implying that some are, and some are not. An ion is a charged particle, a waterfall produces additional ions in the air without the involvement of radon or other ionizing radiation.

Engineers rough estimate rule: if you can't do it in your head then draw it.Also who said it had to be a high velocity, and I'm really replying to the odd and obviously completely incorrect:

It's not obvious to me that it is true that a "grassy area" has less surface area than a wooded area

If it's not obvious then sketch it. I don't entirely buy the rubbing idea anyway, so I'm reacting to the very strange statement about less surface area. It's not as if a tree is just a tall stalk of grass, there are leav

This has been known for a very long time and it's very much common knowledge. Ambient negative ion levels can even be obtained through weather services in my country. My Daikin air conditioner even claims to keep ambient ion levels at "lush forest" levels and it's not near new. Just do a google search for "forest negative ion" and you'll find tons of products and articles on the subject. Why is this at all news?

A few searches will give you quite a few hits for detailed analysis but I'll give you a quick rundown of how I understand it:

What are the implications?

Higher concentrations of negative ions in the air basically leads to "cleaner" air. The basic idea is that the negative ions are attracted to positively charged particulates which they latch on to and break down. Negative ions can also break down bacteria. More details in this wikipedia article: https://en.wikipedia.org/wiki/Air_ioniser [wikipedia.org]

Do the levels of various ions in the air impact human health in any way?

Yes but I'm not personally aware of how much and I'm not sure how much scientific study could have a corporate bias behind it (to sell air purifiction technologies). Reguardless, it's pretty much been scientifically proven that particular levels of negative ions (not too much, but above a certain level) have human health benefits. Some studies I've seen claim negative ion rich environments make the environment more physicall comfortable (more refreshed and energized) to the body which leads to higher energy and lower stress - and personally that's why I purchased higher quality air conditioners and filtration units which I do *feel* make my living and working spaces more comfortable.

How do they differ in cities vs suburbs vs the countryside?

I'm assuming it is -generally- true that cities would likely have lower concentrations than the suburbs which would in turn have lower concentrations than the countryside.

This is the first time I think I've ever made the claim but I did so because they presented the article like they'd JUST NOW discovered it and this was something revolutionary and that bothered me. The title/description is also completely misleading: [negative] ions are concentrations of electrons but they are not "electricity". On top of that the actual study they did found absolutely no new information and yet they are basically claiming they did. Well, actually the article claims they did - the scientist

At first I was thinking "more positive and negative ions... Wouldn't they be attracted to each other and take care of that? Then I read TFA.

"Trees act as radon pumps, bringing the gas to the surface and releasing it to the atmosphere through transpiration - a process where water absorbed by the root system is evaporated into the atmosphere from leaves. This is especially prevalent for trees with deep root systems, such as eucalypts."

The QUT scientists estimated that, in a eucalyptus forest, trees may account for up to 37 per cent of the radon in the air when transpiration rates were highest.

So... If I go into the forest, I'm more likely to be breathing radon, and at greater concentrations? Um... I do like the trees, but from this I'm not sure the feeling is mutual...

There was a guy I read about in one of those kooky FORBIDDEN SCIENCE books you have to order from the back page of a catalog that also sells spirit crystals, dream catchers and cheap swords. I didn't get to read the entire chapter on him, but he was utilizing a system of rods stuck into the ground hear trees to harness energy. It seemed to be pseudo-science of the most laughable sort at the time, but now, I dunno. He could have been on to something.

I certainly don't know any such thing. In fact I thought forests were net zero oxygen because when trees die the decay of the tree consumes as much oxygen as the tree produced during its life. Not to mention that of course at night the tree is burning the sugars it made during the day by photosynthesis.

Plankton is where there is a possible net oxygen increase because when they go dead they can sink, and when that happens they don't decay.

I certainly don't know any such thing. In fact I thought forests were net zero oxygen because when trees die the decay of the tree consumes as much oxygen as the tree produced during its life. Not to mention that of course at night the tree is burning the sugars it made during the day by photosynthesis.

If that were true, why does the global atmospheric CO2 concentration (whilst obviously increasing year after year) have a seasonal oscillation with its phase matched to the growing season of the northern hemisphere (which has an excess of forests rather than ocean)?

Plankton is where there is a possible net oxygen increase because when they go dead they can sink, and when that happens they don't decay.

It might be the production of carbon-rich soil that you're overlooking.

The article seems to imply that radon gar is actually taken up and transpired by trees, but that isn't really the case, is it? I think it's more likely the radon gas is being precipitated* from ground water as tree roots take it up. The consequences are of course still the same, I'm just questioning the implied mechanism.

Perhaps the trees aren't directly responsible for the findings -- I mean, the story makes it sound like the trees are actually creating electricity themselves,but perhaps it is more a result of wooded areas, meaning that since the wooded areas tend to give wind resistance, the wind is less likely to disperse these negative ions, so they tend to become more concentrated there.

I'm working on my Master Gardener certification. And I can tell you that EVERY element trees absorb or expel is ionized. Trees don't interact with anything but anions and cations. So there's that! Nothing a $250 course in plants wouldn't have taught you!

something i noticed while looking for some land to buy, the only trees the usa has left in any large areas is in national and state parks.

That's not entirely true. I live in Maine. Indeed, it was pretty much clear cut a century ago. At that time, it was only about 20% forested. We simply cleared much of the land in order to farm. Over the last 100 years, we have moved away from agriculture and the state is now about 90% forested. Very little land here is actually in the hands of the feds or the state. In fact, about 2/3 of the land area is owned as large parcels (millions of acres) by private timber companies.

I've been wondering about that.....recently I drove across the midwest, and I noticed a lot of plots of land have grown trees as they are no longer used for farming.

How does that happen? Why do people stop using their land for farming? Do they just keep it to have a nice place to spend a weekend? Or is the land so cheap that they don't actually worry about paying property taxes?

How does that happen? Why do people stop using their land for farming? Do they just keep it to have a nice place to spend a weekend? Or is the land so cheap that they don't actually worry about paying property taxes?

I can't speak for the midwest but in New England there were once a lot of fairly small farms. If a house comes with an additional 5-50 acres of property, at $1000 an acre for rural land, it may not add a great deal to the cost of the house. If it's wetland, and therefore difficult to develop or harvest timber from, around here it might go for $500 an acre. Many people with a few tens of acres in this area are engaged in small scale timber harvesting so having the extra land isn't necessarily a financial burden.

As far as taxes, some people will place "the back 40" in to tree growth. State law here allows a landowner to develop a timber harvest plan and get a significant reduction on property tax. In unincorporated parts of the state, I've heard this amounts to $1/acre per year in total tax. I don't know how much of a tax rebate individuals get inside an incorporated town but it is very significant. A number of communities have been complaining about the state mandated tax abatement program and urging reforms because of abuse. For example, owners of waterfront property have been known to place the land into tree growth even though they couldn't possibly harvest the timber due it's close proximity to water -- environmental laws. Of course, this is some of the more expensive property as well.

When I lived outside Seattle I heard of tax abatement programs for landowners who use their property for agricultural uses. Some of the requirements were pretty minimal. We had neighbors who stabled horses or bread a horse per year specifically so they could receive abatements which were only available for land used for agriculture. Property taxes were quite high there so I can certainly see the appeal of working the system.

As far as taxes, some people will place "the back 40" in to tree growth. State law here allows a landowner to develop a timber harvest plan and get a significant reduction on property tax. In unincorporated parts of the state, I've heard this amounts to $1/acre per year in total tax.

Florida is trying to move in this direction at a State level, but the rural county tax collectors would shrivel up and blow away if they couldn't soak owners of conserved lands for residential level taxes.

something i noticed while looking for some land to buy, the only trees the usa has left in any large areas is in national and state parks.

That's not entirely true. I live in Maine. Indeed, it was pretty much clear cut a century ago....

Many other parts of the country have similar stories. Trees were clear cut a century ago.

My land in Florida was clearcut in the late 1800s, more for a quick buck at the sawmill than to grow anything on it - they built a town downriver with all the pine, then the town burned in about 1905. My land has been more or less ignored since then, some neighbors graze cattle.

We bought 160 acres of densely forested land a while back. The only part not wooded were a few acres at the front that had been used as farmland. One summer we rented a tree planter, pulled it behind a tractor and in a matter of 3 days planted 70,000 trees. (they're really cheap when you buy them in that volume) We also raised turkeys and released them into the wild (illegally) and brought the wild turkey back to the county in question over a period of 10 years or so. As we put out more and more broods the neighbors started getting involved. Some of our neighbors started gathering roadkill and leaving them in piles in strategically placed areas with pre-made nesting boxes... now we have bald eagles. I'm not sure where the bears and cougars came from but I'm sure there are similar stories involving them that I don't know about. The simple fact is, as a child growing up in the 70's, there were NO big game animals in that area besides deer. There were a few grouse and pheasant but that was about it. Now the countryside is so rife with wildlife we're starting to have problems with Car+bear accidents. It's an amazing change. If there's one thing the USA has got going for it, it's the return of the wilderness.

While I applaud your spirit, I condemn your reckless hippie bullshit. The bears and cougar showed up because there's food around, good job on acclimating some large predators to humans (slow clap).

If you're really afraid of bears and cougars, move to a city, there's plenty of urban areas to choose from.

I don't think we need to eradicate wildlife (including large predators) from every place humans live, and "studying the problem" endlessly and carefully managing reintroduction doesn't work nearly as well as the Chernobyl approach of just stepping back and letting it happen.

The way we're paving the world, if they don't get acclimated to humans, they're going to become extinct. I'd much rather see them have their own space (see my sig-blog), but until that happens, species like the Florida panther are going to have to figure out how to co-exist, or perish.

Don't put this all on the panthers unless you either somehow don't see us as sentient actors or just don't give a shit about the ecosystem disruption from apex predators going extinct. Both species need to figure out how to co-exist.

One important thing to do is not feed them irresponsibly, essentially guaranteeing they become a public safety issue and thus fail to co-exist.

Blah blah blah...I think nature will handle your "cautious manner" consideration. So what if cougars are stalking me, or bears jump out in front of my car. I'd say you need a quick education on the state of industrial pollution, nuclear proliferation, and human rights if you need something to worry about.

...impact on other species, disease, imbalances in the flora, etc

I'm so sick of hearing this crap. The same can be argued in opposition to preserving a waning species. Nature will take care of the impact, it has successfully done so for a long time now.

You've already pointed out one major unintended consequence, and there are sure to be plenty more... some good and some bad.

I'm so sick of hearing this crap. The same can be argued in opposition to preserving a waning species. Nature will take care of the impact, it has successfully done so for a long time now.

You could argue that only if you're as ignorant as the people who thought introducing the European Starling to North America was a good idea.

The waning species are generally waning because of human actions, particularly habitat destruction. They are natural parts of their ecosystems. Letting them die off damages those ecosystems of which they had evolved to be part of. Nature does not "take care" of the impact like that phrase implies when talking about human actions. Nature solves the problem by not ca

"It is estimated that—at the beginning of European settlement—in 1630 the area of forest land that would becomethe United States was 1,045 million acres or about 46percent of the total land area. By 1907, the area of forestland had declined to an estimated 759 million acres or34 percent of the total land area. Forest area has been relativelystable since 1907. In 1997, 747 million acres—or33 percent of the total land area of the United States—was in forest land. Today’s forest land area amounts toabout 70 percent of the area that was forested in 1630.Since 1630, about 297 million acres of forest land havebeen converted to other uses—mainly agricultural. Morethan 75 percent of the net conversion to other usesoccurred in the 19th century."

And it does go on to describe the kinds of differences - one of which you mention - between historical and contemporary forest composition.

Trees aren't equal. Fast-growing trees drain nutrients but absorb little CO2, for example. Very damaging to the environment, if planted in excess - which is why it is common in the US. Plantations are also not "woods" in any meaningful sense - woods aren't just trees, but complex ecosystems that include wildflowers, fungi, etc. Real woods don't generally have massive wildfires, those are almost invariably the consequence of plantations or excessively-managed areas. Not always, true, but natural forests with natural clearings and natural recycling of raw materials will tend to utilize forest fires to sweep out excessive trash and allow seedlings to grow -- this is obviously not possible when the heat destroys even the fire-resistant seed pods/cones and topsoil.

1) One would think a fast growing tree would have to absorb CO2 (and nutrients) in order to build all that cellulose quickly.

2) If that tree is subsequently harvested (and a new one replanted) and converted into timber, or paper that ends up in archives or landfills it means more CO2 locked up for years (yes paper manufacturing is normally environmentally unfriendly but it doesn't have to be so)

Well, it is not immediately clear from the GP, but the draining/absorbing comes from different sources. While CO2 absorbtion is mostly from the air (which is why plants can grow bit in pots with little change to the soil), the nutrients are generally taken from the ground, thus "draining" it, in the absence of fertilizer or some other way to return nutrients to the ground. Most notable of these nutrients, and what is usually the limiting factor, is nitrogen (specifically, nitrates). Some trees actually leav

Wood releases its CO2 back into the air with a half-life of about 60 years, paper is much shorter than that. I can confirm this too. The cedar in my 100 year old house is lighter than balsa, meaning that the person who "over built" the house with 2x12s every 18 inches actually just planned for the future.

If you really want to get rid of the CO2, you must burry it, even shallowly, to prevent it from degrading.

You don't know what you're talking about. Trees are good as habitat, and for erosion... but CO2? The vast, vast majority of CO2 absorbed is done so by algae in the oceans. Trees are barely a blip. Pines grow fast and burn easily which enriches the soil. Clearly you dont live anywhere where there's a forest but when you do... there are fires. The pines burn quickly. The oaks survive... the pines leave ash which makes the soil less acidic and acts as fertilizer. Most pinecones only open when heated by fire... that's evolution for you. The phoenix trees.

Where do you live? In Florida, it's the pines that are fire adapted and the oaks that burn. If a fire is hot enough / the pines are small enough, the pines die too, but pre-European settlement, Florida had vast old-growth pine forest which experienced natural (lightning ignited) fires every few years.

Today, the oaks don't burn either because they live in damp bottomlands that don't burn easily due to moisture content, or because fires in oak forest are actively suppressed. Many pine forests in Florida to

Very damaging to the environment, if planted in excess - which is why it is common in the US.

Contrary to your statement (belief?), U.S. land owners do not actively seek to damage the environment, they do occasionally seek a quick payout which has the same effect, but land managers aren't really trying to destroy Bambi's home.

"The study showed that when phosphorus or nitrogen -- which occur naturally in rain forest soils -- were added to forest plots in Costa Rica, they caused an increase in carbon dioxide emissions to the atmosphere by about 20 percent annually, said Cleveland. "